Various industries and material handling systems feed wet, slurry like materials through different process steps. For example, in the food industry, dough, batter, coagulated dairy products, etc. must be uniformly fed onto conveyor or processing belts that move such unfinished products along a series of food processing steps. In mining operations, water is used to reduce dust levels at the mines and quarries. The wet freshly mined ores and/or fines are fed onto conveyor belts. Wet ores tend to be sticky, and therefore, they are difficult to distribute uniformly across the endless belts that carry such raw materials away from the mine. In metallurgical industries, including the steelmaking industry, stringent EPA requirements have made it necessary to install gas cleaning and wastewater treatment systems at refining operations in order to meet water and air discharge standards. The effluent generated by such wastewater treatment equipment is often processed to recover valuable metallurgical materials (reverts), and the recovered revert material is recycled back into the manufacturing operation. Wastewater treatment systems usually include a filtration step, and it is necessary to provide a uniform distribution of slurry across the filter belt in order to effectively dewater slurry. Failure to provide a uniform slurry distribution results in poor dewatering of the slurry and/or damage to filter belts.
For example, in a belt filter, slurry is pressed at high pressures between two endless belts. Any irregularity in the slurry distribution such as uneven slurry depth or voids in the slurry material distributed across the belt width will generate high-localized pressures that result in tearing the belts. Such damage requires shutdown of the operation for repair, and therefore, is costly in both time and capital. In instances where the slurry is filtered using a vacuum filter, airflow through the distributed slurry material follows the path of least resistance, and any irregularity in slurry depth will cause rapid dewatering along thinner slurry depths and incomplete dewatering at the thicker slurry depths. Additionally, any voids in the distributed slurry material will cause a complete loss of vacuum and no dewatering of the slurry. In the past, in order to avoid such belt damage and dewatering problems, polymers were added to iron and steelmaking scrubber slurries to form a gelatinous mass that operators were able to rake into a substantially level layer across the width of the filter belts. However, such polymers are expensive additives, and their high cost offset any savings realized by efforts to recover the iron and carbon particles for recycling backing into the manufacturing process. Raking the gelatinous mass also requires the use of additional man-hours to insure an even distribution of slurry is fed onto the filter press.